1. Field of the Invention
The present invention relates to an adapter device for holding a blade having a first and a second side onto a distal end of a holder of a spade drill. More particularly, the present invention relates to an adapter device for the passage therethrough of coolant, the device permitting holding a blade having a first and a second side onto a distal end of a holder of a spade drill.
2. Background Invention
Spade drills are used in machine tools for boring relatively large diameter holes in a workpiece and for generating various configurations at the base of the drilled bore.
Typically, a spade drill includes a holder which is removably secured to the turning mechanism of the machine tool. The distal end or working end of the holder includes a drill point and cutting edges extending generally radially from the drill point so that as the holder rotates, the cutting edges guided by the drill point progressively bore through the workpiece.
However, such cutting edges may break or become subjected to excessive wear. Accordingly, the entire spade drill must be replaced thus requiring resetting of the machine tool in order to achieve the required tolerances. Accordingly, spade drills have been proposed in which the cutting edges are replaced by removable inserts. Such an arrangement is disclosed in U.S. Pat. No. 4,642,001 to Hunter et al.
As taught in the U.S. Pat. No. 4,642,001, a carrier block supported by the holder has a first and a second insert with each insert having four cutting edges so that any of the four cutting edges can be positioned to do the cutting.
The present invention provides a unique arrangement for locating a single blade having two cutting edges within an adapter which may be rapidly secured to the distal end of a holder. The arrangement is such that the adapter device and blade can be readily replaced by another adapter device having the same size blade or a different sized blade without any need for resetting the machine tool.
Therefore, it is a primary feature of the present invention to provide an adapter device for a spade drill that overcomes the problems associated with the prior art arrangements.
Another feature of the present invention is the provision of an adapter device for a spade drill that facilitates the changing of a blade.
A further feature of the present invention is the provision of an adapter device for a spade drill that permits the use of a variety of blades without any need for resetting a machine tool.
Another feature of the present invention is the provision of an adapter device for a spade drill that avoids the need for replacing an entire spade drill when a blade thereof becomes worn or broken.
Other features and advantages of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description of a preferred embodiment of the present invention contained herein.